Lock key



June 27, 1933. c, MAXWELL ET AL 1,915,897

LOCK KEY Filed April 28, 1955 [N VENTOR i4 TT ORNE y Patented June .27,1933 UN E STATES PATENT OFFICE LOCK KEY Application filed April 28,1933. Serial N0. 669,894.

This application is a continuation in art of our application, Serial No.578,994, ed on December 4, 1931, for a lock, the new structure formingan improvement thereon.

The invention relates to anti-pick locking devices, and more especiallyto means for preventing the picking of tumbler cylinder locks andespecially those having plate or disc tumblers. It is an object of ourinvention to devise a key, for a lock where the lock has for cooperationwith the key, a shutter or other keyway controlling and determiningmember. This controlling member is adapted to operate in the keyway of acylinder plug, and to be actuated by the particular key of ourinvention, so that unless the particular key is utilized, it will beim'- poss ble to release and rotate the plug n a conventional manner.

More particularly it is the object of our 1 invention to devise a keyhaving longitudinally connected portions lying in different planes, witheach portion having special cooperation with locking tumblers, the keybeing as an entirety cooperable with a keyway determining member whlchis adapted to control the longitudinal and cross-sec:

tional shape of a composite keyway. The

preferred form which I will disclose embodies a key having. a bladewhich is bent to form parts forward and rearward of said bent portioncooperable with locking elements arranged for operation in different d1-rections. 0

Referring now to the drawing wherein a modification of our invention isshown, Fig. 1 shows a key adapted for the particular plug which wepreferto utilize, Fig. 1A being a side view thereof. Fi s. 2 and 2Aillustrate front and side views 0 a cylinder lock showingthe applicationof our invention. Fig. 3 shows parts of the cylinder constitutlng ourinvention in the order in which they are assembled. Fig. 4 is asectional view of the plug and cylinder with the tumblers removed. Fig.5 is a section along the lines 5-5 of Fig. 4, while Fig. 6 is a sectionalong the lines 6-6 of Fig. 4. Fig. 7 is a view similar to Fig. 5showing a modified form of shutter. Figs. 8 and 8A are side and topviews of a key cooperable with the modified shutter of Fig. 7.

Referring now more'particularly to the drawing, and especially Fig. 4,it will be noted that we employ a plug 10 having a keyway 11 through themajor portion thereof, and a series of tumbler chambers 12 leading intothe keyway and having tumblers "therein adapted to be actuated by a keyin a manner well known to those skilled in the art. Each of the tumblersis spring pressed by a spring 13 (Fig. 6) in an upward lockng directionso that its head portion 14 locks into a roove 15. Preferably, the headsof the tum lers are shaped as shown in the form of a T, and cooperatewithsimilarly formed complementary slots in the main cylinder slot 15,so that surreptitious rotation for picking purposeswill interlock thetumblers 7o securely to the cylinder.

The keyway 11 is of normal size for cooperation with the key of Fig. 1,but is enlarged at the front of the plug, so as to form a relatlvelywide portion 16. Preferably,

the front end of the plug is formed by cooperation of an insert section17 adapted to fit into a cutaway portion 18 of the plug, so that the twowill form the conventional type of plug front. The function of the twoparts of the plug front is to form between them,

an opening 19, this opening forming the bearing for a shutter 21 and aspring 20, which latter is adapted to press the shutter into the plug,as indicated in Figs. 4 and 5.

The end of the shutter cooperating with with bit 22, it will force a legportion 28 of the shutter into a cooperating slot 29 in the cylinder.Similarly, if any other portion of the shutter is contacted by animproperly shaped or manipulated tool or key, the portion 28 will bemoved into the slot 29 to interlock the plug-and cylinder. This acts tomaintain the plug and cylinder against relative rotary movement duringthe insertion of the key and makes for easy key action be cause thetumblers do not ride hard against the walls-of slot 15 as is the casewhen the key is inserted with an incidental slight turning of the plug.It also prevents the application of the rotary torque to the plugrequired to assist in the use of a picking tool other than one shapedlike the key. As will be indicated later, the shutter functions also toprevent the -use of a picking tool even if shaped like the key ofFig. 1. Once the key has been fully inserted, the hole 23 willcorrespond to the bit 22, and the leg portion 28 will be spring pressedout of the slot 29, so that if the tumblers have been properlyposilioned, the plug will now be free for rotation relatively to thecylinder.

As will be quite apparent, the operation of the shutter in cooperationwith the enlarged portion 16 of the keyway, acts to so limit thelongitudinal shape of the keyway as viewed in Fig. 2, that it isnecessary to use the ofi'set key shown in Fig. 1. The key will properlybe inserted against the bits 24 and 25 which ride in the grooves 26 and27 of the key, guiding it until the end of the key abuts the slopingportion 31a from which point it is guided into the narrow portion 11 ofthe keyway. In its final position, thekey will have part thereof lyingin the narrow opening portion below the shutter illustrated in Fig. 4,while its tumbler setting portion will rest in the keyway 11, thusforming, in effect, a key having parallel leg portions and operating ina keyway of the same shape.

It will be furthermore apparent that the operation of the bit 22, andthe bits 24 and 25 cast integrally with the plug will so limit the widthof the keyway that the insertion of a tool for surreptitiously settingthe tumblers will be very diflicult, and operation of that tool willmore than probably cause movement of the shutter into a plug lockingposition, thus preventing the application of picking torque as hasalready been indicated. it a picking tool shaped like the key of Fig. lis utilized for picking the tumblers, it is quite obvious that anyslight rotation of the plug from its position of Fig. 5, as willnecessarily be required to apply picking torque thereto, will lock theshutter 20 in positive ofi'set keyway determining position, since thetongue 28 will be removed from opposite the slot 29. It will then beimpossible to withdraw the key shaped picking tool, or to move itbackwards and forwards as is necessary if it is to act individually onthe tumblers as is understood by those skilled in the art.

Preferably, also, an armor cap 31 is adapted to fit over the insert 17and the plug 10 and to be pressed over as shown in Fig. 4 to protect thefront of the plug, and hold the parts in assembled relation.

in Fig. 7 we illustrate a modified form 32 of the shutter 21 of Fig. 3.This shutter has an angular extension 33 which is adapted to cooperatewith the cut-away part 34 of the key 35 of Fig. 8 which is the key forwhich the shutter 32 is designed. The bit 22 of the shutter willcooperate with the milled roove 36 on the key. The key and shutter 0Figs. 7 and 8 cooperate in the same manner as the key and shutter of myfirst modification except that the keyway is more accurately defined anda lesser degree of movement of a picking tool is possible.

While we have shown a preferred modification of our invention, it shouldbe understood that we consider it to be broad in character and believeourselves entitled to dominate the modifications of the same which arewithin the scope of the appended claims and which will readily occur tothose skilled in the art.

VVeclaim:

1. A key for a lock having a blade comprising forward and rearwardoffset parallel portions. the upper vertical edge of one of saidportions being adapted for hitting whereby to cooperate with locktumblers, and a side face on the other of said portions having apredetermined contour for cooperation with a keyway determining memberof the lock.

2. A key for a lock having a blade comprising forward and rearwardofi'set portions, the upper vertical edge of one of said portions beingadapted for hitting whereby to cooperate with lock tumblers, and a sideface on the other of said portions having a predetermined contour forcooperation with a keyway determining member of the lock.

3. A key for a lock having a blade comprising forward and rearwardoffset portions connected by an angular portion, the upper vertical edgeof one of said portions being adapted for hitting whereby to cooperatewith lock tumblers, and a side face on the other of said portions havinga predetermined contour for cooperation with a keyway determining memberof the lock.

4. A key for a lock having forward and rearward offset portionsconnected by an angular portion. the. forward one of said ofisetportions having a series of bittings on its upper vertical edge, a sideface of the rearward offset portion having a predetermined contour forcooperation with a keyway determining member, said side face lying in aplane )lth.

ill"

intermediate the planes of the two outside parallel surfaces of saidkey.

5. A key for a lock having forward and rearward ofi'set portions, theforward one of said offset portions having a series of bittings on itsupper vertical edge, a side face of the rearward offset portion having apredetermined contour for cooperation with a keyway determining member,said side face lying in a plane intermediate the planes of the twooutside parallel surfaces of said key.

6. A key for a lock having a lock mechanism operating blade comprisingforward and rearward longitudinal connected poreach of said portionshaving a surface tions,

lock controlling mechanism,

nism operating blade comprlsing forward and rearward longitudinalconnected portions,

the forward of said portions being adapted for hitting at its upper edgeonly for cooperating with vertically movable tumblers, the rearward ofsaid portions constructed at its side for cooperation with ahorizontally movable locking member, each of said portions lying indifferent planes.

8. A key for a lock having a blade formed of a metal strip bentintermediate its ends to form two portions lying in different planes,the for-ward of said portions being adapted for hitting along an upperedge for cooperation with tumblers movable parallel to the plane of thatportion, the rearward of said portions constructed for cooperation witha locking member movable at substantially right angles to the plane ofsaid rearward portion.

9.'A key having forward and rearward longitudinally extending connectedportions lying in different planes, the forward of said portions beingadapted for hitting whereby to cooperate with tumblers moving parallelto the plane thereof, the rearward of said portions having a face ofsuch contour as to properly cooperate with a lock controlling elementwhich is positioned by said rearward element depending upon thedisplacement of the plane of said rearward portion from the forwardportion as well as upon the contour of the face of said rearwardportion.

10. A key for a lock having a blade formed of a metal strip bentintermediate its ends and forming forward and rearward longitudinalportions joined together by an angular bent portion, the key portionforward of said bent portion being constructed for hitting along anupper edge for cooperation with tumblers movable parallel to the planeof that portion, the key portion rearward of said bent portion beingconstructed for cooperation with a locking member movable atsubstantially right angles to said rearward portion.

11. A key for a lock having a blade formed of a metal strip bent anddeformed intermediate its ends and forming forward and rearwardlongitudinal portions joined together by said bent deformed portion, the

key portion forward of said deformed portion being constructed forhitting along an upper edge for cooperation with tumblers movablesubstantially parallel to the plane of that portion, the key portionrearward 0 said deformed portion being constructed for cooperation witha locking member movable at substantially right angles to the directionof movement of the aforesaid tumblers.

Signed at Stamford, in the county of Fairfield, and State ofConnecticut, this 27th day of April, 1933.

